Dell POWEREDGE R805 - Manual (Page 9)

Getting Started With Your System
7
Installing the Rails and System in a Rack
Once you have read the "Safety Instructions" located in the rack
installation documentation for your system, install the rails and the system
in the rack.
See your rack installation documentation for instructions on installing
your system in a rack.
Connecting the Keyboard, Mouse, and Monitor
Connect the keyboard, mouse, and monitor (optional).
The connectors on the back of your system have icons indicating
which cable to plug into each connector. Be sure to tighten the screws
(if any) on the monitor's cable connector.